Ultrastructure of Proechinophthirus zumpti (Anoplura,Echinophthiriidae) by scanning electron microscopy

The ultrastructure of Proechinophthirus zumpti Werneck, 1955, mainly the external chorionic features of the egg, is described through electronic microscopy techniques. This species was first cited in Argentina, infesting Arctocephalus australis (Zimmermann, 1873). The morphological adaptations of adults and nymphs are described in both species of Proechinophthirus parasitic on Otariidae: P. fluctus (Ferris, 1916) and P. zumpti.     

<Emphasis Type="Italic">Coccocarpia tomentosa</Emphasis>, una nueva especie de Argentina (Ascomycetes liquenizados,Peltigerales, Coccocarpiaceae)

In this paper Coccocarpia tomentosa, from Misiones, Argentina, is described and illustrated. Comments on five related species also known from Paraguay and Brazil are included. The known distribution of C. pellita is extended and it is cited for the first time from Argentina.     

Rust fungi causing galls, witches' brooms, and other abnormal plant growths in northwestern Argentina

Conspicuous galls and witches' brooms frequently are symptoms of rust infections on plant hosts in the ecologically diverse northwestern region of Argentina. These symptoms are caused by systemic or locally systemic spermogonial-aecial infections, although uredinial and telial infections also might be involved. Sixteen species of rust fungi are treated in this paper, most of which cause a plant response that results in enlarged growth. Ypsilospora tucumanensis J.R. Hern. & J.F. Hennen on Inga edulis is described as a species new to science. Puccinia cordiae Arthur is cited as a new record for Argentina. These rusts also are included: Chaconia ingae, Gerwasia imperialis, Kuehneola loeseneriana, Prospodium appendiculatum, Prospodium elegans, Prospodium perornatum, Puccinia bougainvilleae, Puccinia pampeana, Ravenelia argentinica, Ravenelia hieronymi, Ravenelia papillosa, Ravenelia spegazziniana, Uromyces cestri and Uropyxis rickiana. For some of the scientific names, lectotype specimens have been designated.     

Gene banking of the neotropical fish Leporinus obtusidens (Valenciennes, 1836): a protocol to freeze its sperm in the field

A practical sperm cryopreservation protocol using a dry-shipper and a diluent of simple composition is described for the neotropical fish Leporinus obtusidens (Valenciennes, 1836). The cooling rate of the dry-shipper and its period of useful time, established under laboratory conditions, were respectively 25.7-30.8 degrees C/min (between 0 and -60 degrees C) and 9 days after charging. Sperm donors were selected on the basis of their hyperemic genital papilla and the ability to ooze milt under gentle manual pressure, during the reproductive months of November to January. Milt volume (1.3+/-0.3 mL; n=9 fish), fresh sperm motility rate (93.3+/-2.5%; n=6 fish), and sperm concentration (10.9+/-3.0 x 10(9)spermatozoa/mL of milt) were obtained. The sperm cryopreservation experiments were conducted with the following cryoprotectants (all at 10%, before mixing with milt): dimethyl sulphoxide (DMSO; n=10 fish), methanol (n=6 fish), propanediol (n=6 fish) and ethylene glycol (n=5 fish). Glucose (5%) and hen's egg yolk (10%) made up the diluents containing DMSO, ethylene glycol or propanediol. Milk powder (10%) replaced hen's egg yolk in the diluent containing methanol. Distilled water (up to 100%) completed the diluent solutions. Milt freezing (in 0.5-mL straws) was performed in the dry-shipper after 1:5 (milt:diluent) dilution. Thawed sperm cryopreserved in DMSO-containing diluent and activated by 119 mM NaHCO(3) gave the highest motility rate (62+/-14%). The fertilizing capacity of L. obtusidens sperm was tested using the combination of DMSO-containing diluent as the cryoprotectant and 119 mM NaHCO(3) as the activating solution. Oocytes were obtained from artificial spawning and fertilized with different proportions of spermatozoa. The greatest rate of fertilization (74%) occurred when the ratio of about 112,000 motile spermatozoa:oocyte was used. Thus, a protocol to freeze L. obtusidens sperm can be elaborated as follows. Milt (<1.5 mL fish(-1)) was readily available only in November to January; a simple solution, composed of 10% DMSO (concentration before adding milt), 5% glucose, and 10% hen yolk egg, in distilled water, was used as sperm diluent; cooling rate of 25-30 degrees C/min, yielded in a portable dry-shipper, was adequate to freeze diluted milt (1:5; milt:diluent), in 5-mL straws; about 112,000 thawed motile spermatozoa:oocyte activated by 119 mM NaHCO(3) assured a fertilization rate of 74%.     

A new Diacyclops (Copepoda,Cyclopoida, Cyclopidae) from northwestern Argentina

No species of the genus Diacyclops has been so far cited from continental Argentina. Specimens collected from a roadside pool in the province of Catamarca on a plateau at 3700 m a.s.l. turned out to belong to a new species, Diacyclops andinus, which is described and illustrated in detail for both sexes. Main diagnostic features are: spine formula of swimming legs 3, 4, 4, 4; terminal spines of the distal endopod segment of leg 4 subequal; smooth furcal rami. The new species is a member of the D. bicuspidatus group, and is probably near the base of this line.     

The taxonomy, biogeography and host plant relationships of jumping plant-lice (Hemiptera: Psyllidae) associated with creosote bushes (Larrea spp., Zygophyllaceae)

Abstract.  The Neotropical genus Panisopelma (Psyllidae: Aphalaroidinae) is revised and its internal phylogeny analysed. The constituent species, including five new ones, are described and illustrated. Keys are provided for the adults and the last instar larvae. Eight species are associated with creosote bushes ( Larrea , Zygophyllaceae): five with L. nitida and three with L. divaricata . There is evidence that another three species, the larvae of which are unknown, also develop on L. divaricata . Seven species are restricted to Argentina, one to Bolivia and three to Chile. The cladistic analysis based on male, female and larval morphological characters yielded a single most-parsimonious tree. The species associated with L. nitida form a monophyletic clade, those on L. divaricata , by contrast, are paraphyletic. One clade with three species is restricted to Argentina, but three clades each contain a species from Argentina and Chile. Although a close association exists between Panisopelma and Larrea , there is no evidence for cospeciation, but rather an initial shift from an unknown host to L. divaricata and a second shift from L. divaricata to L. nitida . In three species pairs of Panisopelma , the distribution patterns suggest geographical vicariance between Argentina and Chile.     

Descriptions of two new species of flea of the genus Plocopsylla in northwestern Argentina

Two new species of flea of the genus Plocopsylla, subgenus Plocopsylla, (Siphonaptera: Stephanocircidae) collected from sigmodontine rodents in northwestern Argentina are described and a key to identification of species of the genus Plocopsylla, subgenus Plocopsylla, in Argentina is presented. Plocopsylla (P.) inti is cited for the first time in Argentina, extending its distribution ～ 970 km further south than previously documented. New locality data and flea–host associations are recorded. The contributions of this study are relevant because they increase knowledge of the diversity of flea fauna in northwestern Argentina bordering a plague endemic area and will be useful in the implementation of plague control management plans in the future.     

Biogeographical revision of Argentina (Andean and Neotropical Regions): an analysis using freshwater fishes

Aim  To provide an objective geographic framework displaying the distribution patterns of freshwater fishes from Argentina.
Location  Argentina, southern South America.
Methods  Parsimony analysis of endemicity (PAE) and similarity and cluster analyses were applied to presence and absence data on 440 fish species from 52 localities in Argentina. Both 50% majority consensus and strict consensus analyses were undertaken in the first case, and the Jaccard similarity index was used in the second.
Results  Five ichthyogeographic provinces are described based on a PAE of the 52 localities. A cluster analysis provided similar results.
Main conclusions  The following zoogeographic provinces are proposed for Argentine freshwater fish fauna following the International Code of Area Nomenclature: Andean Cuyan, Patagonian, Aymaran, Great Rivers and Pampean. The former two are placed within the Andean Subregion of the Austral Region, and the latter three within the Neotropical Subregion of the Holotropical Region. These provinces, based on results coinciding with PAE and cluster analysis, represent the first classification of Argentine provinces based on objective methods. Some small regions of endemism and some localities remain separated from the proposed regions. The new scheme includes valuable empirical information from previous schemes, and is in agreement with ecological zones and other environmental arrangements proposed earlier.     

Length–weight relationships of eight fish species from the lower section of the Uruguay River (Río Negro, Uruguay)

This study reports length–weight relationships for Apareiodon affinis , Leporinus obtusidens , Cynopotamus argenteus , Loricariichthys melanocheilus , Parapimelodus valenciennis , Iheringichthys labrosus , Rhinodoras dorbignyi and Pachyurus bonariensis . Specimens were collected between 2006 and 2007 from the lower section of the Uruguay River. The study represents the first reference on weight–length relationships for three species and also provides the new maximum size for three species.     

Lesser Sandplover,Charadrius mongolus,in Turkey

Sagittal otoliths are widely used to determine taxon, age and size of the teleost fishes, and are useful tools for studies of prey-predator relationships, population dynamics and ichthyo-archaeology. They can also be used to estimate the size of the prey. We examined the relationships between otolith measurements (length, height and weight) and fish size (total length and weight) for two species of Argentinidae (Argentina sphyraena and Glossanodon leioglossus) from the Southern Aegean Sea, Turkey. Length, height and mass of sagittae were shown to be good indicators for the length and weight of fish in both species. Glossanodon leioglossus has relatively larger sagittae than Argentina sphyraena. Linear and exponential functions provided the best fit for relations between otolith and fish measurements. No significant differences were found between left and right otolith sizes.     

Processes that drive the population structuring of Jenynsia lineata (Cyprinidontiformes,Anablepidae) in the La Plata Basin

1. The distribution of genetic diversity across a species distribution range is rarely homogeneous, as the genetic structure among populations is related to the degree of isolation among them, such as isolation by distance, isolation by barrier, and isolation by environment.
2. Jenynsia lineata is a small viviparous fish that inhabits a wide range of habitats in South America. To decipher the isolation processes that drive population structuring in J. lineata, we analyzed 221 sequences of the mitochondrial cytochrome c oxidase I gene (COI), from 19 localities. Then, we examined the influence of the three most common types of isolation in order to explain the genetic variation found in this species.
3. Our results revealed a marked structuration, with three groups: (a) La Plata/Desaguadero Rivers (sampling sites across Argentina, Uruguay, and Southern Brazil), (b) Central Argentina, and (c) Northern Argentina. A distance‐based redundancy analysis, including the explanatory variables geographical distances, altitude, latitude, and basin, was able to explain up to 65% of the genetic structure. A variance partitioning analysis showed that the two most important variables underlying the structuration in J. lineata were altitude (isolation by environment) and type of basin (isolation by barrier).
4. Our results show that in this species, the processes of population diversification are complex and are not limited to a single mechanism. The processes that play a prominent role in this study could explain the high rate of diversity that characterizes freshwater fish species. And these processes in turn are the basis for possible speciation events.

     

Characterization of blood cells and hematological parameters in Cichlasoma dimerus (Teleostei, Perciformes)

The aim of the present study was to obtain a basic knowledge of the hematology of Cichlasoma dimerus. The morphological features of blood cells were described according to the observations made by light and electron microscopy. Erythrocytes, thrombocytes and four types of leucocytes: lymphocytes, monocytes, heterophils and eosinophils, were distinguished and characterized. Thrombocytes are the most abundant blood cells after erythrocytes and are recognized easily from lymphocytes by morphological features and size. Heterophils and eosinophils are PAS positive. Hematological indices (RBC, WBC, PCV, Hb, MCV, MCH, MCHC and leucocyte differential count) were measured in one blood sample from 30 adult fish captured in Esteros del Riachuelo, Corrientes, Argentina (27 degrees 25'S, 58 degrees 15'W). The reference interval and the mean were determined for each hematological parameter evaluated. Contrary to other species, the percent of heterophils was found to be high in relation to the percent of lymphocytes. Low lymphocyte counts occurred in C. dimerus, as compared to these found in other fishes. Compared to most teleosts, this species has similar mean values for PCV and Hb and slightly higher for RBC. Statistical analysis revealed that differences in hematological parameters between male and female fish were not significant.     

Pseudochakura (Hymenoptera: Eucharitidae), a New World genus of chalcidoids parasitic on ants

Abstract. The genus Pseudochakura Ashmead (Eucharitidae: Eucharitinae) is revised to include thirteen species which all share the complete fusion of the genae behind the mandibles and a loss of functional mouthparts. Eight Neotropical and one Nearctic species of Pseudochakura are described as new: atra (Mexico), condylus (lesser Antilles), excruciata (Brazil), frustrata (Argentina), liburna (Florida, U.S.A.), pauca (Argentina), prolata (Argentina), sculpturata (Brazil; Florida, U.S.A.), septuosa (Mexico). P. chilensis Kieffer is redescribed. The known distribution of P.nigrocyanea Ashmead is extended to Uruguay and Venezuela. The known distribution of P. americana (Howard) [comb.n.] is extended to Panama, Columbia, Ecuador, Argentina and northward into the southern tip of Florida. All three previously described Nearctic species are synonomized under the name P.gibbosa (Provancher) with P.arizonensis (Crawford) and P.californica (Ashmead) as junior synonyms. Biological information is summarized providing new information on both plant and ant hosts. A phylogenetic hypothesis for the genus is nresenteri.     

Notes on Echinodorus (Alismataceae)

Errors by Rataj in lecto- and neotypification of five names inEchinodorus are corrected. These errors include the selection of lectotype specimens that were not cited in the protologue and the designation of neotypes from syntypes. Lectotypes for four of the names are designated here. The other is not typified at this time, as we have as yet been unable to examine the cited collections. In addition, a lectotype is designated for the Linnaean nameAlisma cordifolia, a name for which Rataj did not choose a lectotype. A new species,Echinodorus reticulatus, is described and illustrated. Five new combinations at the subspecies level are proposed, with most of these subspecies having a distribution from Central America to Paraguay and Argentina.     

Three New Genera of Small Minnow Mayflies (Insecta: Ephemeroptera: Baetidae) from the Andes and Patagonia

Three new genera and three new species of Baetidae (Insecta: Ephemeroptera) are described from the Andes and Patagonia. Larvae of Andesiops, new genus, are distinguished by the apically bifid right prostheca and two rows of denticles on the tarsal claws. Larvae of Deceptiviosa, new genus, are distinguished by the apically bifid right prostheca and small subapical denticle on the tarsal claws. Larvae of Nanomis, new genus, are distinguished by the apically acute maxillary palp segment 2, smooth posterior margin of the terga, and paddle-shaped subapical seta on the hindtibiae. Adults of Andesiops and Deceptiviosa are similar, but distinguished from other South American baetids by having hindwings with a small costal process in the basal one third and three lon gitudinal veins with the middle vein being forked, and an elongate and ellipsoidal genital forceps segment 3. Larvae and adults of Andesiops peruvianus, new combination, are redescribed, and additional locale data are provided for Argentina, Bolivia, Ecuador, and Venezuela. Deceptiviosa ardua, new species, is described from larvae from Chile, and D. torrens, new species, is described from larvae and adults from Chile and Argentina. Nanomis galera, new species, is described from larvae from Argentina, Colombia, Ecuador, and Peru.     

New Dalyelliidae (Platyhelminthes, Rhabditophora) from Buenos Aires Province, Argentina, and their stylet ultrastructure

Two new species of Dalyellidae, Dalyellia callvucurai n. sp. and Gieysztoria namuncurai n. sp., are described from temporary freshwater environments in central Buenos Aires Province, Argentina. The ultrastructure of the stylets of both species is also described. The new species of the genus Dalyellia is the second species of the genus found in the neotropics and the first whose stylet has been studied with scanning electron microscopy. Gieysztoria namuncurai n. sp. joins the seven species of the genus known in Argentina. The ultrastructural characteristics of the stylet place it in the Inaequales group, with complex stylets.     

Length–weight relationships of 13 fish species from Pahang River,Temerloh district,Pahang, Malaysia

Length–weight relationships (LWRs) are described for 13 fish species from Pahang River, Temerloh district, Pahang, Malaysia. The river serves as a main water body for freshwater aquaculture in the country and also supplies various fishes for local consumption. This is the first record of LWRs for nine fish species and new maximum lengths for three species in fishbase .     

First report of Temnocephala brevicornis Monticelli 1889 (Temnocephalidae: platyhelminthes) in Argentina

Temnocephala brevicornis Monticelli 1889, ectosymbiont of Hydromedusa tectifera Cope 1869, is reported for the first time for Argentina. Numerous temnocephalans from Arroyo Villoldo in the locality of Magdalena, Buenos Aires, Argentina were stained in toto to be studied. This commensal species in turtles was originally cited in association with Hydromedusa maximiliani (Mikan) and Hydraspis radiolata Mikan in Brazil. Afterwards, it was found on other fresh water turtle species in Brazil and Uruguay.     

New metacercariae of the genus Tylodelphys (Trematoda, Diplostomatidae) in lacustrine populations of Galaxias maculatus (Teleostei, Galaxiidae)]

Metacercariae of three new species of Tylodelphys (Trematoda, Diplostomatidae) were found in the brain of Galaxias maculatus (Teleostei, Galaxiidae), at the Meliquina Lake, Neuquen Province, Argentina. These metacercariae are morphologically described as Tylodelphys argentinus n. sp., Tylodelphys barilochensis n. sp. and Tylodelphys crubensis n. sp. This is the first time that a stage of genus Tylodelphys is mentioned parasitizing Galaxias maculatus. Metacercariae of T. barilochen sis n. sp. were also found in G. maculatus brain at the Perito Moreno Lake, Rio Negro Province, Argentina.